Simple string used as artificial horizon?

T8 wrote:

He then mentioned that way back in the early days of flying they would
simply tape a string hanging from the ceiling to act as an artificial
horizon.

It's not April 1 already is it?

Just put a mark on your canopy and spit at it. If spit flies left of
target, you are turning right and vice versa.

-T8

NOW you're talking.
There was a D-I_Y autopilot design which used a blower tube streaming
air onto four thermistors arranged pairwise-differentially. This gave
pitch rate and yaw rate, or if mounted skew, inputs on all three axes.
These days, a three axis acceleraometer goes for $25 and rate sensors
for a little more... One well known Arduino project ["ArduPilot"]
offers the guts of an autopilot suitable for driving R/C servoes, which
will easily fit in a medium size model plane. I expect this could easliy
fit in a homebuilt...

Brian W

karen wrote:
/snip/
The other reassuring thing was that stupid little string hanging there
told me what was straight up and down, when my senses said we were
banked and slipping or skidding./snip/
Michael

....but now you realise that it would have stayed straight up and down
even in a steep balanced turn, of course....

Brian W

Ever watch Bob Hoover video of him pouring a glass of ice tea.. or was it
lemonade.. with one hand while rolling his AeroCommander with his other
hand. He had a ball on a string below the board that held his glass. The
board was mounted to his glare shield. He kept the ball centered below the
glass through the entire roll 1G roll. You can see the real horizon through
the front windshield as he rolled.

Strings in cockpits are only slip skid indicators, as someone else also
posted.

BT

"bildan" wrote in message
...
On Dec 29, 10:37 am, mattm wrote:
On Dec 29, 11:45 am, T8 wrote:

On Dec 29, 11:25 am, GARY BOGGS wrote:

I am amazed that anyone with a pilots certificate would actually think
anything hanging in the cockpit would tell you anything about the
horizon!!!! Please tell me these aren't certified pilots!

Gary

I'm with you there, Gary.

The spit bit, I may need to clarify, was intended as wry humor.

-T8

A number of years ago an article in The Atlantic magazine by William
Langewieche (son of
S&R author and current Vanity Fair chief editor) described an old
story that an airline pilot
had used a pocket watch as a turn indicator when his gyros failed. WL
tried it by flying out
over the open ocean, where the horizon disappears. He hung a pocket
watch from the ceiling
of the cockpit and used it as a pendulum. The pendulum DID work as a
crude turn indicator
but it tended to dampen out after a few swings. Nonetheless, if/when
ever stuck in the soup the
correct approach is the benign spiral. It does pay to try that
whenever you get checked out
in a new plane so you have confidence it will save your butt.

-- Matt

Nothing is quite as terrifying as pilots with zero "hood time"
discussing how to fly in clouds.

A weight on a string simply works as a poor ball bank by indicating
slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
or pitch. A ball or yaw string are far better instruments. A ball
will work even when a wet yaw string is stuck to the canopy.

If you think trying with this looks like fun, PLEASE find an old
school instrument instructor (CFII) and an old airplane with a "turn
and bank". Ask for some "partial panel" (Needle-Ball-Airspeed)
instruction. (Airplanes newer than ~1965 will have the cursed 'turn
coordinator' which indicates nothing but turbulence by wiggling.)

The killer is panic. Virtually every first timer will panic when his
gut sense and the instruments say different things - and they WILL be
different. The most basic instrument flying skill is to suppress what
you feel and concentrate on what the instruments are saying. That can
be VERY difficult.

Andy wrote:

Anything hanging in the cockpit like a pendulum (or any instruments
working on the same principle) DOES NOT tell you which way is up./snip/

9B

If you are going to take on the school master role, you had better be
right. Current solid state angular rate sensors act like a mini pendulum
or tuning fork - when turned, the pendulum retains spatial inertia.
Foucault, an' all that. Remember?

Brian W

bildan wrote:

A number of years ago an article in The Atlantic magazine by William
Langewieche (son of
S&R author and current Vanity Fair chief editor) described an old
story that an airline pilot
had used a pocket watch as a turn indicator when his gyros failed. WL
tried it by flying out
over the open ocean, where the horizon disappears. He hung a pocket
watch from the ceiling
of the cockpit and used it as a pendulum. /snip/
-- Matt

Nothing is quite as terrifying as pilots with zero "hood time"
discussing how to fly in clouds.

A weight on a string simply works as a poor ball bank by indicating
slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
or pitch.

Ho hum: there is ONE thing more terrifying than pilots with zero hood
time giving advice - and that's pilots with or without hood time who
don't think twice before speaking once.

A pendulum is NOT a plumb bob.

Brian W

"Bruno" wrote in message
...
I had a very interesting conversation yesterday with a very
experienced pilot (older) who has spent a lot of time in some amazing
aircraft starting with the P51 Mustang and going up to jets including
the SR-71 blackbird and as we were looking over my glider we started
talking about the yaw string on the canopy.

He then mentioned that way back in the early days of flying they would
simply tape a string hanging from the ceiling to act as an artificial
horizon. I've never heard this one before! Next person who reads
this who goes up tape a string hanging from the inside of the canopy
and tell us how it works. Now you have another reason to take off
work and go soaring.

Bruno -B4
http://www.youtube.com/user/bviv

Watch the white ball on the end of the string in this video starting at
about 2:00 (but do yourself a favor and watch the whole thing):

http://www.alexisparkinn.com/photoga...bob_hoover.avi

Question answered?

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

On Dec 29, 5:19*pm, brian whatcott wrote:
T8 wrote:

He then mentioned that way back in the early days of flying they would
simply tape a string hanging from the ceiling to act as an artificial
horizon.
It's not April 1 already is it?

Just put a mark on your canopy and spit at it. *If spit flies left of
target, you are turning right and vice versa.

-T8

NOW you're talking.
There was a D-I_Y autopilot design which used a blower tube streaming
air onto four thermistors arranged pairwise-differentially. This gave
pitch rate and yaw rate, or if mounted skew, inputs on all three axes.
These days, a three axis acceleraometer goes for $25 and rate sensors
for a little more... * One well known Arduino project ["ArduPilot"]
offers the guts of an autopilot suitable for driving R/C servoes, which
will easily fit in a medium size model plane. I expect this could easliy
fit in a homebuilt...

Brian W

One thing I think would work is pitot tubes on each wing tip connected
to a Winter type variometer with the vario rotated so the needle
pointed up. Air would flow from the faster wing tip to the slower one
through the vario which would show rate of turn. It's the only "non-
gyro" rate of turn instrument I can think of.

On Dec 29, 4:34*pm, brian whatcott wrote:
bildan wrote:
A number of years ago an article in The Atlantic magazine by William
Langewieche (son of
S&R author and current Vanity Fair chief editor) described an old
story that an airline pilot
had used a pocket watch as a turn indicator when his gyros failed. *WL
tried it by flying out
over the open ocean, where the horizon disappears. *He hung a pocket
watch from the ceiling
of the cockpit and used it as a pendulum. /snip/
-- Matt

Nothing is quite as terrifying as pilots with zero "hood time"
discussing how to fly in clouds.

A weight on a string simply works as a poor ball bank by indicating
slips and skids but says NOTHING WHATSOEVER about bank, rate of turn
or pitch.

Ho hum: there is ONE thing more terrifying than pilots with zero hood
time giving advice - and that's pilots with or without hood time who
don't think twice before speaking once.

A pendulum is NOT a plumb bob.

Brian W

Such an energetic conversation! And the list had ben such a quiet
place... In this case I think you are both right. Yes a pendulum is
not a plumb bob. But it will also not tell you which was is up- which
is what Andy stated. I might be a viable rate and direction of turn
indicator in a pinch. I would imagine if you tried to start swinging
it once you had entered a turn, it would only go in circles or
ellipses, but...

I rather like the idea! I can imagine a little square of velcro on
the inside of the canopy where the yaw string is taped down, so it
didn't cut out visibility during normal flight. Then maybe a short (8
inch?) piano wire with a fishing weight at one end and a loop at the
other that goes through one of those cable tie pads with mating
velcro. All stashed in the side pocket.

Now the cloud layer closes below me and I must make an emergency
decent through an IFR layer. I velcro my pendulum to the canopy, head
into the wind, start it swinging fore and aft, and pull the spoilers.
Nothing to it.

Please someone try this right away (without the clouds!) and report
back to the list. I want one.

Matt

"GARY BOGGS" wrote in message
...

I am amazed that anyone with a pilots certificate would actually think
anything hanging in the cockpit would tell you anything about the
horizon!!!! Please tell me these aren't certified pilots!

Amen. It is completely possible to have the string pointed at the floor in
a 90 degree bank, or even upside-down.
--
Jim in NC

OK guys, why not just install a relatively inexpensive turn and bank?
We flew actual instruments with them for years. They spin up fairly
fast and don't need to be on all the time. If you want to keep it
seperate from the main electrical system, you could install a small 2
AH battery that would power it for a long time.